Setting shutter leaf rebound latch



P 5, 1939- I w. A. RIDDELL 2,172,295

SETTING SHUTTER LEAF REBOUND LATCH FilediMarch 4, 1938 William A.RiddellINVENTOR ATTO EYS Patented Sept. 5, 1939 UNITED STATES PATENT OFFICESETTING SHUTTER LEAF REBOUND LATCH Application March 4, 1938, Serial No.193,889

8 Claims.

This invention relates to photography and more particularly tophotographic shutters.

One object of my invention is to provide a shutter with a mechanism fornormally latch- .5 ing the shutter blades in a closed position, thislatch being releasable by setting the shutter. Another object of myinvention is to provide a shutter master member which must be manuallyset and to provide connections between a shut- 10 ter blade ring latchand the setting member by which the blade ring latch will be renderedinoperative only when the master member has been set. Still anotherobject of my invention is to provide a shutter of the setting type inwhich 15 the blade ring is rocked back and forth by one latch connectedto the master member and is held in a latched position by a second latchcarried by the shutter. A still further object of my invention is toprovide a shutter in which any 20 possible rebound by the master membercannot be transmitted to the shutter leaves and in which rebound by themaster member will not permit the shutter blade ring to also rebound,thus making a partial double exposure. Other objects 25 will appear fromthe following specification, the novel features being particularlypointed out in the claims at the end thereof.

In photographic shutters which are susceptible of producing high speeds,particularly ex- 30 posures from to 15 of a second, the master memberhas to travel at high speed and it is very difficult to occasionallyprevent a certain amount of rebound in the master member which occurswhen it suddenly comes to rest after hav- 35 ing made an exposure.Shutters of this type require that the shutter master member be manuallyset before an exposure can be made because with the automatic type ofshutters, it is impossible to move the parts at a suihciently high 40speed.

With shutters of the type described, it sometimes occurs that aconsiderable amount of rebound by the shutter member may allow theleaves to partially open again, thus occasionally 45 spoiling theexposure.

My present invention is particularly directed to preventing the reboundof the master member from allowing a rebound of the blade operatingring. The blade operating ring, of course,

50 must move exceedin ly rapidly, and with the type of shutter whichwill next be described, the blade operating ring moves back and forth asthe master member moves from a tensioned position to an untensionedposition so as to rock a 5. latch which connects the master member tothe blade ring back and forth for an exposure. With this type ofshutter, the latch moves idly without operating the blade ring as theshutter is tensioned.

Coming now to the drawing wherein like reference characters denote likeparts throughout:

Fig. 1 is a plan view of a typical shutter constructed in accordancewith and embodying a preferred form of my invention. In this view theshutter cover is removed and all of the mechal0 nism which is notpertinent to this invention is omitted.

Fig. 2 is a view similar to Fig. l, but showing the master member andassociated parts in a position which they might assume after a fastexposure has been made.

Fig. 3 is a view similar to the preceding figures with the parts intheir normal position of rest.

Fig. 4 is a fragmentary detail perspective view of the two latchelements and their relation to the blade ring lug.

As indicated in Fig. l, the shutter may comprise a casing member Ihaving an upstanding flange 2 extending around the edge and having theusual exposure aperture 3 which is normally covered by a plurality ofshutter blades 4 which may be of the shape shown in Fig. 3. Each bladeis pivoted at 5 to the shutter casing and has an extension 6 slotted atl to receive a pin 8 carried by a blade ring 9.

This blade ring be oscillated back and forth to cause the shutter leaves4 to open and close to make an exposure in a known manner by means of anupstanding lug [9 which projects upwardly through a slot H in the plate[2 into a position in which it may be engaged by the blade ringoperating mechanism.

In the present instance, the lug I0 may be oscillated back and forth bythe latch member I3 which is provided with a hook M which engages thelug [0 when the parts are in the proper position. The latch member i3 ispivotally attached at [5 to the master member Hi, this member includinga hook H which may be engaged by an arm l8 carried by the trigger [9which projects through an opening 20 in the shutter casing. The triggeris pivotally attached at 2| to the plate I2 and the master member ispivotally mounted on a stud 22 also carried by the plate l2.

The master member is provided with a manual setting lever 23 by whichthe master member [6 may be moved from the position shown in Fig. 3 tothe position shown in Fig. 1 in order to tension the spring 24 which isconnected to the master member at 25 and to the plate l2 by means of apin 26. The master member latch I3 is provided, as best shown in Fig. 4,with a hook I4 which may engage the blade ring lug l and with two arms21 and 28. The former is for releasing the spring latch 30 as will behereafter more fully described, and the latter is to normally swing thelatch member l3 into engagement with the lug l0. As will be seen fromFigs. 1 and 4, the upstanding arm 28 of the latch l3 engages a lightspring 3|.

With shutters constructed as above described, it sometimes occurs whenthe shutter is operating at high speeds that the master member I6, incoming to a stop by striking the casing edge 32,

' as shown in Fig. 3, causes a slight rebound upon its pivot 22 so thatthe master member and latch l3 may move to the position shown in Fig. 2.When in this position, it will be seen that the hook I4 is not inengagement with both sides of the lug l0, and consequently, the bladering 9 may also tend to rebound when lug I0 strikes the stop comprisingthe end 33 of the slot H in plate l2 through which it operates. It istherefore possible for the blades to spring open, sometimes as far as isshown in Fig. 2, if it were not for the spring latch 30, which will nowbe described. The spring latch 30 is provided with a hook end 35 and theopposite end is attached to a stud 35. The spring latch 30, through thespring in the wire of which the latch is made, tends to turn the latchin the direction shown by the arrow so that it will normally engage theblade ring lug I!) and hold it in the position shown in Fig. 3. This isthe normal position of rest.

When the shutter is to be set, the setting lever 23 is moved in thedirection shown by the arrow in Fig. 3, placing the spring 24 undertension and catching the latch members I! and 18 together as shown inFig. 1. During the setting movement, the upstanding arm 21 on the latchl3 will engage a portion of the spring wire 30 moving the bent end 35out of engagement with the blade ring lug I0, as indicated in Fig. 1.Thus, when the shutter is set and is in position for an exposure to bemade, the latch 30 is inefiective.

By depressing the trigger [9, the operating latch I3 rapidly oscillatesback and forth and carries the upstanding lug ID with it, opening andclosing the shutter. be a very fast exposure, the arm 23 may strike theshoulder 32, travelling at a rather high speed and the master membermay: rebound. However, as soon as the upstanding arm 2'! moves away fromthe spring latch 30, the spring latch again presses on the lug l0 andwill engage it in the bent end 35 just as soon as the blade ring lugreaches the position shown in Fig. 3. Thus, even if the master membershould rebound from this position, moving the arm 28 away from the lugID, the lug I0 still cannot rebound at the same time by striking thestop 33 because of the spring latch 30.

As above described, I have provided a shutter in which the settingmember may travel at a high speed and may rebound without afiecting theexposure. Even though the rebound may occur in the master member, itcannot occur in the blade ring because the blade ring is latchedseparately from the master member so as to hold the blades in a normallyclosed position. The arrangement of the blade ring latch is such that bysetting the shutter and placing the spring of the master member undertension, the latch is manually re- If the exposure should leased at thesame time the shutter is set so that the blade ring will be in positionfor exposure.

What I claim is:

1. In a shutter, the combination with a casing, of mechanism thereincomprising shutter blades, a blade ring, a lug on the blade ring foroscillating it to open and close the blades, a pivoted master member, asetting lever projecting from the casing for manually tensioning themaster member, a trigger projecting from the casing for releasing themaster member, a pair of latches, one connected to the master member andadapted to engage the lug for opening and closing the blades, the otherconnected to the shutter for normally holding the shutter blades closed,and means for releasing the second latch actuated by setting theshutter.

2. In a shutter, the combination with a casing, of mechanism thereincomprising shutter blades, a blade ring, a lug on the blade ring foroscillating it to open and close the blades, a pivoted master member, asetting lever projecting from the casing for manually tensioning themaster member, a trigger projecting from the casing for releasing themaster member, a pair of latches, one connected to the master member andadapted to engage the lug for opening and closing the blades, the otherconnected to the shutter for normally holding the shutter blades closed,and means carried by the first latch for releasing the second as theformer is moved in setting the shutter.

3. In a photographic shutter, the combination with shutter blades, of ablade ring, a lug carried thereby for moving the blades, a pivotedmaster member including a spring, a lever for setting the master memberplacing said spring under tension, stops for limiting the movement ofthe master member, a latch carried by the master member adapted toengage the lug for opening and closing the shuttee blades, and a secondspring latch member positioned to engage the lug in the normal positionof rest when the blades are closed to prevent possible rebound of themaster member from partially reopening the shutter blades by strikingsaid stop.

4. In a photographic shutter, the combination with shutter blades, of ablade ring, a lug carried thereby for moving the blades, a pivotedmaster member including a spring, a lever for setting the master memberplacing said spring under tension, stops for limiting the movement ofthe master member, a latch carried by the master member adapted toengage the lug for opening and closing the shutter leaves, a secondlatch carried by the shutter comprising a light spring wire bent to forma shoulder to engage the blade operating lug and normally tending toturn thereagainst, each of said latches being adapted to engage said lugwhen said master members rest against a stop.

5. In a photographic shutter, the combinatiton with shutter blades, of ablade ring, a lug carried thereby for moving the blades, a pivotedmaster member including a spring, a lever for setting the master memberplacing said spring under tension, stops for limiting the movement ofthe master member, a latch carried by the master member adapted toengage the lug for opening and closing the shutter leaves, a lightspring latch for engaging the lug and means carried by the first latchfor releasing the second latch as the master member is set toward onestop, said spring latch being adapted to engage the lug when said mastermember moves against the other stop.

6. In a photographic shutter, the combination with shutter blades, of ablade ring, a lug carried thereby for moving the blades, a pivotedmaster member including a spring, a lever for setting the master memberplacing said spring under tension, stops for limiting the movement ofthe master member, a latch carried by the master member adapted toengage the lug for opening and closing the shutter leaves, as the mastermember oscillates upon its pivot, a pivot for connecting the latch tothe master member, said pivot being positioned to swing the latch andwith it the lug back and forth for making an exposure when the mastermember moves to a normal position of rest, and to swing the latch idlypast the lug when the shutter is set, a second spring latch for holdingthe lug in a position to hold the shutter blades closed, and meanscarried by the first latch and adapted to engage the second latch forreleasing the latter during the setting movement in which the firstlatch moves without moving the lug.

'7. In a photographic shutter, the combination with shutter blades, of ablade ring, a lug carried thereby for moving the blades, a pivotedmaster member including a spring, a lever for setting the master memberplacing said spring under tension, stops for limiting the movement ofthe master member, a latch carried by the master member adapted toengage the lug for opening and closing the shutter leaves, as the mastermember oscillates upon its pivot, a pivot for connecting the latch tothe master member, said pivot being positioned to swing the latch andwith it the lug back and forth for making an exposure when the mastermember moves to a normal position of rest, and to swing the latch idlypast the lug when the shutter is set, a second spring latch for holdingthe lug in a position to hold the shutter blades closed, and aprotuberance carried by one edge of the first latch in position toengage the second latch during the idle stroke of the former in settingthe shutter whereby the second latch is released when the master memberis set.

8. In a shutter, the combination with a casing, of mechanism thereincomprising shutter blades, a blade ring and a lug on the blade ring foroscillating it to open and close the blades, a master member, a levermeans for manually setting the master member, a stop defining oneposition of the master member, means carried by the master member forlatching the lug temporarily to move with the master member and forreleasing the lug, a spring latch for normally engaging the lug, meanscarried by the master member latch for releasing the spring latch whenthe master member is set, the master member lug latch being driven to aposition to release the lug by actuating the shutter trigger before themaster member reaches its stop whereby said spring latch may be free toengage said lug and prevent rebound which may otherwise occur when saidmaster member strikes said stop.

WILLIAM A. RIDDELL.

